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Expensive Preamplifiers = Big Scam?

Jon_Logan said:
There is no impedance matching at audio frequencies. The output impedance is low and the input impedance is high.
[snip]
If there was trouble with the source unit driving an interconnect and input impedance, the same situation would exist driving a pre-amps input too.
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Impedance "match" might not be the best term, but a lot of pro audio guys would be out of business if it were just low to high. There ARE variables.

Slagle's autoformers do have bass rolloff if the input impedance is too high. Not all tube devices have such low output impedance, and freq response becomes an issue.

But there is more to it than impedance matching when it comes to overhead and dynamics.
 
A couple of years ago I replaced my great McIntosh C33 preamp with a new McIntsh C46 simply because I wanted a preamp with a remote control. I was amazed at the improvement in overall sound. Call it depth, whatever but it led me to up date the other Mac stuff too.
 
So let me see if I am up to speed here....some like preamps...Some don't. That about cover it....I would have to say that everything is in equilibrium here.


Me I tend to be in the like them camp....
 
cableguy said:
So let me see if I am up to speed here....some like preamps...Some don't. That about cover it....I would have to say that everything is in equilibrium here.
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Yup, that sums it up.

Hey WAIT, you left out the we-like-autoformer guys! :grumpy:

Sometimes I think it comes down to 1) some like to try out lots of things, and THEN voice an opinion, while 2) some like to voice an opinion about maybe not bothering to try out lots of things.

Despite the near-consensus about the importance of system, I'm not seeing a lot of people tell their story about what they found in their system in terms of comparison and conclusion.
 
Turbino: I agree with the majority of what you have said; although the whole impendence-matching argument at audio frequencies is flawed.

I don't want to get caught-up in this argument, so I will state my piece and then exit this thread.

So-called "Passive" preamps are incredible in terms of transparency, but they do subjectively suck some of the life (or dynamics) out of the music by rounding the leading edge of the waveform. This is inherently caused by the fact that such a device inherently forms a low-pass filter when cable capacitance is added to the mix. This failing is just as true of switched resistor networks as it is of potentiometers. Auto-transformers do not have this issue, but can still color the music in other regards.

Simply buffering a "passive" with an op-amp can address the dynamics issues of the passive, but it introduces all of the problems of the op-amps. So you really do _not_ get the best of a passive preamp combined with the best of an active. You simply get an active preamp without gain.

Active preamps can sound lousy, or they can sound fantastic, or they can be anywhere in-between. It all depends on the particular design. Some designs like the classic Audio Research SP-10, and SP-11 strived for to achieve absolutely neutral gain, which that had no "sound" to it whatsoever. These units were more successful than most designs either before or since that time in this particular regard.

But some other designs, such as Conrad -Johnson gear tended to have a very clear romantic tube sound to it. Likewise solid state gear can very greatly on the "neutrality" scale. Some sounding absolutely atrocious, some sounding OK, and some sounding really good.

Ultimately the choice of whether to use a preamp or not is purely subjective, unless you happen to need the gain. Let your ears decide what you like the best. The Yamaha receiver referenced at the beginning of this thread is so far from the best, it doesn't even warrant a comparison. Obviously running without a preamp will be a huge benefit for such a system. But inserting a really good preamp, could be even better, depending upon your tastes.

Going by specs and measurements will tell you almost nothing about how a given preamp actually sounds. Personally, I'd recommend inserting a good tube preamp into the chain if you want to be introduced to a whole new world of sound. Most won't be as transparent as a passive (though some will), but they can really make your music sound a whole lot better, despite what all of the nay-sayers say. But ultimately the choice is yours as to whether you desire to take comfort in a spec sheet with vanishingly low distortion numbers, or you want to actually listen to and enjoy your music.
 
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The better pre's sound better so no pre would be best argument IMO has never panned out. I have 2 valve CDP players that have volume controls and very low output impedence and I have ran them direct into every amp I own and IMO preamps are better and better preamps are better still.

marc mc
 
tubino said:
Yup, that sums it up.

Hey WAIT, you left out the we-like-autoformer guys! :grumpy:

Sometimes I think it comes down to 1) some like to try out lots of things, and THEN voice an opinion, while 2) some like to voice an opinion about maybe not bothering to try out lots of things.

Despite the near-consensus about the importance of system, I'm not seeing a lot of people tell their story about what they found in their system in terms of comparison and conclusion.
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My thoughts exactly....Plenty of meter reading stat guys....I tend to lend my ears more readily to people whom share from experience...firsthand listening experience that is.
But that said, everyone here is entitled to their own path to sonic bliss.
 
yep, and some are still fooled by sloppy evaluation techniques where they allow psychology and hope to influence their choice.

I'm all for a listening test, but for God sakes make it a good test with a switch and somebody elses hand on the toggle. Match the volumes etc. I used to tricked until I was more careful. If you know which one you're listening to, there'll be a bias (error). If the volumes arent matched, there'll be an error.

I really take exception to the final, desperate, argument that if you apply a scientific test that your a "stat guy". How would anybody know whether, or not, I've tried any of these things? Maybe I have and the more care I took in testing, the less the differences existed? I could say the sky is twelve feet tall. It would be rediculous to test that I'd think.

The poster asked if a CD player could directly connected to an amp and sound good. My answer is "yes". Then there was some points made about impedances, speaker thermal compression and how a preamp somehow magifys the signal into something more than the CD player's output. Sure, my opinion is different then some. I also know that a good test of this might change some other minds.

BTW, I use a preamp. It is a Home Theater preamp. Lexicon DC-1. It sounds great, has great decoders in it etc. If there was a situation where I had one source, there'd be nothing stopping me from driving my amp directly.

Passive volume controls? I have used Leader 600 ohm attenuators and with the 600 ohm output, you can drive long cables with them. You can just do the math and figure out what kind of high frequency hit you're gonna get. Backing up nonsense with poor test techniques will not forward the hobby that is scientifically based. The green ink on discs went out years ago. Don't get me started on speaker wires sitting on dixie cups. This too is proven "effective" with sloppy listening tests.
 
Jon_Logan said:
I'm all for a listening test, but for God sakes make it a good test with a switch and somebody elses hand on the toggle. Match the volumes etc. I used to tricked until I was more careful.
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Did you ever hear a system with life-like dynamics, that fooled you from the next room that it might be live? When you switched out a preamp, did you ever have a spouse or girlfriend notice a change in the sound from the next room, WITHOUT KNOWING YOU CHANGED ANYTHING, and without particularly caring about equipment? (My wife can tell right way, sometimes just asking, "Why doesn't it sound as good?" when I change something, and no, it's not visual cues.)

It's easy to be skeptical, but can you offer any relevant story of a preamp comparison? For example, it would really fit in if you had a story of ABX comparing your HT preamp with a pro audio piece on a high-efficiency compression driver hornloaded system, like the one I mentioned hearing at AK Fest. (I've done this with Ampex 350 decks, NAD HT preamp, high-end tube preamps, autoformers, etc.) Honestly, I would like to participate in anything like that.

A few years back, when the SWTMS group in southwest Michigan got all high and mighty about ABX testing, they mentioned needing volunteers. I offered. Repeatedly. Couldn't make it happen.

I think ABX testing is just fine. It's just curious how the loudest proponents have so little interest in trying it with anything I find remotely interesting, but maybe I just missed it. If you have something relevant with preamps, please share it. The desperate attempt to compare this discussion with green ink on CDs leads me to think you have no relevant experience, frankly.
 
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Here is my take on the subject. I have run both passive, solid state, and tubed pre's.

My general preference generally falls towards the Tubed Pre, I understand, that the sound qualities I'm enjoying are indeed distortion, But ........Wow do I like it's got to say. My second preference has been a passive pre. In my opinion this is the most absolute purest sound obtainable.

Third and least enjoyable in my opinion, is the solidstate pre. It might work for some of your systems, but does not match up with mine very well.
 
I bought a Crown DC-300A II because it was such a good buy(i thought anyway). Brought it home, cleaned it out and to test it I hooked up an old NAD cd player I use in my garage. No preamp, just straight in.
Was very disappointed at first. For a 155wpc amp into 8 ohms, 300 into 4 ohms, it was not nearly as loud as I thought it should be, thinking it needed some major work.
To make sure tho, stuck a preamp between them - there is not a problem with the amp.
If what you have works and you are satisfied, no need to get a preamp.
For me, even if the cd player had enough gain, I still need a preamp as I have more then one source on all of my stereos -
Yes, the path of least resistance is best, but for most, finding a satisfying preamp is pretty much a necessity.
 
nedgar said:
Not really trying to troll here; I just need to be edumacated.

I'm in the market for a preamp.

I have a few pairs of modest but nice speakers (small Thiels, small Martin Logans, and small a/d/s/ towers) and a few good power amps (McIntosh MC250, Adcom 555 and a very nice sounding Xindak).

I only have two rooms suitable for listening, so I rotate the equipment from the attic, museum style, every few weeks. The two things that stay unchanged in each room are the CD players and the Yamaha HTR-5790 receivers (with pre-outs) which I use as preamplifiers/surround processors.

The McIntosh and Xindak amps have volume control pots, so they can be used without preamplifiers. Just for fun, I tried hooking up the CD players directly to the amplifiers, bypassing the Yamahas, and lo and behold: it sounds MUCH BETTER! The Yamahas seem to really degrade the sound.

So, isn't the function of a preamplifier ideally to simply get out of the way? Need it be more than a selector switch and a high quality potentiometer (excepting the phone stage for turntables).

What am I missing?
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are expensive pre-amps a scam?
yes and no..

YES-if you bought it and it sucks in your system..:no:

NO-if you bought it and YOU are TOTALLY blown away by its performance..:yes:
 
goldear said:
Going by specs and measurements will tell you almost nothing about how a given preamp actually sounds. Personally, I'd recommend inserting a good tube preamp into the chain if you want to be introduced to a whole new world of sound. Most won't be as transparent as a passive (though some will), but they can really make your music sound a whole lot better, despite what all of the nay-sayers say. But ultimately the choice is yours as to whether you desire to take comfort in a spec sheet with vanishingly low distortion numbers, or you want to actually listen to and enjoy your music.
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The best way to select a preamp is by listening to it. The preamp that I think sounds best is a solid state Yamaha, the CX-10000. By the way, you're pushing the supposed superiority of tube preamps pretty hard.
 
Mark B said:
The best way to select a preamp is by listening to it. The preamp that I think sounds best is a solid state Yamaha, the CX-10000. By the way, you're pushing the supposed superiority of tube preamps pretty hard.
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I listened to a number of preamps. I still have some. In my experience the well-designed tube ones trounce the solid state ones. Could there be a solid state one I like more, if I just gave it a chance? Sure, why not.

Somewhere I have an HK Cit I that surprised me first by the size of the power transformer, and second by the sound, which was pretty darned good for something that looked awfully complicated. Somewhere I have a pair of Lafayette KT-300s, mono versions of the famous KT-600. I can't figure out why they sound so good, in an old tube way... but modern ones with octals are really much better.
 
tubino said:
I listened to a number of preamps. I still have some. In my experience the well-designed tube ones trounce the solid state ones. Could there be a solid state one I like more, if I just gave it a chance? Sure, why not.

Somewhere I have an HK Cit I that surprised me first by the size of the power transformer, and second by the sound, which was pretty darned good for something that looked awfully complicated. Somewhere I have a pair of Lafayette KT-300s, mono versions of the famous KT-600. I can't figure out why they sound so good, in an old tube way... but modern ones with octals are really much better.
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I used to believe that tubes were automaticly better, but a recent Luxman purchase side by sided with an ARC SP-8 changed my world. The SP-8 is a classic. The Luxman has me listening to new sounds on all my old recordings. Plus it has a certain seductiveness that makes you stop what your doing, find the sweet spot and fall into musical revery.
 
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